1. Field of the Invention
This invention generally relates to a motorized bicycle actuator assembly. More specifically, the present invention relates protecting a motor and drive train of a bicycle component when a malfunction occurs that results in the motor being energized longer than necessary.
2. Background Information
Bicycling is becoming an increasingly more popular form of recreation as well as a means of transportation. Moreover, bicycling has become a very popular competitive sport for both amateurs and professionals. Whether the bicycle is used for recreation, transportation or competition, the bicycle industry is constantly improving the various components of the bicycle.
In particular, bicycle components have become motorized so as to increase the performance of the bicycle and the ease of operating the bicycle. For example, one part of the bicycle that has been motorized is the transmission or drive train of the bicycle. Thus, many bicycles have been provided with an electronic drive train for smoother shifting. These electronic drive trains include a rear multi-stage sprocket assembly with a motorized rear derailleur and a front multi-stage sprocket assembly with a motorized front derailleur. These derailleurs are electronically operated by a cycle computer for automatically and/or manually shifting of the derailleurs.
A typical bicycle transmission is operated by a shift operating wire connected between the transmission and a manually operated shift operating device mounted on the handlebar. The rider operates the shift operating device to selectively pull or release the shift operating wire which, in turn, operates the transmission in the desired manner. In a motorized bicycle transmission, the rider pushes a button and a motor is activated to operate the derailleur for completing a shift operation.
One problem with motorized bicycle components is that the motor may overrun due to faulty electrical cables or other electrical components. Moreover, the motor may overrun due to the bicycle component being out of adjustment. If the motor overruns, the drive train for operating the bicycle component may become damaged due to the gear train constantly coming to an abrupt stop.
In view of the above, there exists a need for a motorized bicycle component which overcomes the above mentioned problems in the prior art. This invention addresses this need in the prior art as well as other needs, which will become apparent to those skilled in the art from this disclosure.
One object of the present invention is to provide a motor of a motorized bicycle component in which the motor and drive train are protected in the event of a malfunction.
Another object of the present invention is to provide a power assist for a front derailleur that protects the motor and drive train in the event of a malfunction.
The foregoing objects can basically be attained by providing a motorized bicycle actuator assembly that protects the parts in the event of a malfunction. The motorized bicycle actuator assembly comprising a motorized actuator unit, a bicycle component operatively coupled to the motorized actuator unit, a control device operatively coupled to the motorized actuator unit to stop operation of the motorized actuator unit at first and second stop positions; and first and second shock absorbing elements arranged to prevent damage when the motorized actuator unit is driven past the first and second stop positions. The motorized actuator unit includes a reversible motor, a drive train operatively coupled to the reversible motor, and a control device operatively coupled to the reversible motor to stop rotation of a drive axle of the drive train at first and second stop positions. The bicycle component operatively is coupled to the drive axle to move a movable member between a first preset component position and a second preset component position that correspond to the first and second stop positions of the drive axle, respectively. At least one shock absorbing element is operatively arranged to cushion movement of the drive train when the drive axle moves past at least one of the first and second stop positions of the drive axle.
According to one aspect of the present invention, the control device is a position switch device operatively coupled to the motor to stop rotation of the drive axle of the drive train at the first and second stop positions. According to another aspect of the present invention, the control device is an overcurrent detecting circuit operatively coupled to the motor to stop rotation of the drive axle of the drive train at the first and second stop positions.
In one preferred embodiment, the bicycle component is a front derailleur. However, it will be apparent to those skilled in the art from this disclosure that the bicycle component can be any motorized bicycle component. For example, the bicycle component of the present invention can be a rear derailleur, a motorized suspension, or any other suitable motorized bicycle component.
These and other objects, features, aspects and advantages of the present invention will become apparent to those skilled in the art from the following detailed description, which, taken in conjunction with the annexed drawings, discloses a preferred embodiment of the present invention.